How many kilometers should Castrol Edge fully synthetic oil be replaced?
3 Answers
Castrol Edge fully synthetic oil should be replaced every 10,000 kilometers. The replacement interval for engine oil depends greatly on the oil quality and external driving conditions. Advantages of fully synthetic oil: Fully synthetic oil has a wider temperature range compared to semi-synthetic and mineral oils; Synthetic oil is less prone to deterioration, has lower evaporation loss, and lasts longer than conventional oil; It exhibits excellent chemical stability, good radiation resistance, high oil film strength with less foam, providing superior lubrication and reduced wear; Fully synthetic oil has minimal thermal degradation, saves fuel, and offers better engine protection. Functions of engine oil: The primary functions of engine oil are to reduce friction and wear between moving parts, and to remove sludge and varnish from the engine. Engine oil, motor oil, or engine lubricant is a substance enhanced with additives in base oil, mainly containing anti-wear additives along with detergents, dispersants, and multi-grade viscosity index improvers.
Using Castrol Edge for these years, my experience is that the official recommendation is to change oil every 1 year or 10,000 km, but it actually depends on the situation. Friends who often encounter traffic jams should consider changing it earlier at around 8,000 km, while those who drive more on highways can extend it appropriately. Last time during maintenance, the mechanic reminded me that this oil has good high-temperature stability, and long-term use can indeed reduce sludge. However, I tested the oil condition with an electronic gauge, and the oil film strength significantly dropped after exceeding 12,000 km. Now, I have a remote monitor installed in the car that displays the oil health every cold start. Once, I forgot to change the oil and drove up to 15,000 km, and the engine sound became rough.
Our fleet's decade-old vehicles have all been using Castrol Edge, and the oil change interval definitely shouldn't rigidly adhere to 10,000 kilometers. Older vehicles experience faster oil seal degradation, especially in the humid southern climate – signs of emulsification can already be seen on the dipstick by 8,000 km. During one engine repair, we discovered that vehicles insisting on 12,000 km oil changes showed 0.3mm more camshaft wear compared to those changed at 8,000 km. Now we conduct TAN (Total Acid Number) testing every 7,000 km and change immediately if the value exceeds 0.8. Last month during heavy rains, the oil moisture test triggered a red alert just after 6,000 km – even the most durable oil needs to respect actual operating conditions.
